While the distance a singer’s mouth is from the microphone will obviously have an impact on the dynamics and volume of that captured vocal, it also has a palpable effect on the frequencies captured, as well. Let’s identify what the proximity effect is with microphones and what to know on a mixing level whether that’s live or in studio.
What is the Proximity Effect
In music production as it relates to vocals and microphones, the proximity effect dictates that the closer a source (in this case the vocalist) is to a directional/cardidoid microphone, the more prominent the bass will be.
As I covered in my overview on polar patterns, a cardioid microphone features a directional pattern, most strongly capturing what’s directly in front of it with a dead space behind it:
This is why beat boxers hold the microphone against their mouths, to more effectively capture that low end “bass” of the vocal percussion.
This is also why broadcasters and radio hosts get right up on the microphone – it brings out more of the deepness and power in their vocals. Conversely, the farther away they position their mouths from the microphone, the thinner their voice sounds.
As an example, if you’ve ever seen a video clip of Howard Stern talking into the microphone, moving the boom stand so that the microphone is directly against his lips, that’s the reason.
The Proximity Effect in Mixing
So we’ve identified what the proximity effect is, why does it matter?
When you’re setting up microphone(s) or setting a level for the microphone, it’s important to set the microphone a responsible distance from the source, particularly with vocalists.
Getting directly up on a microphone makes the vocal especially boomy which may be what you’re going for, but it’s the movement that causes problems. Typically in the studio, a vocalist is much more likely to stay stationary than in a live setting.
As I covered in my recent tutorial on how to EQ live vocals, the proximity effect can be a bigger issue in a live setting.
Ironically, vocalists have more of a habit of holding microphones directly up to their faces when performing live.
This is why you typically need to be more aggressive with high pass filtering vocals live, going 50-100 Hz higher than you would in the studio because the vocal can get too boomy without that aggressive filtering.
The main thing to understand about the proximity effect is the impact it can have on any source, regardless of their fundamental range.
While it’s more of an issue with instruments more capable of boominess like a kick drum or vocals, it’s important to be aware of the unnatural and oftentimes unwanted boominess which will be present if you mic your source too close.
Six inches is generally a good rule of thumb for microphone to source distance, but listening live to hear the frequency response with that source playing is always the best way to nail the distance.
Speaking of ideal distance, check out my 14 tips on how to record acoustic guitar for a complete overview on proper miking techniques.
